Can't Use Printer Port for Serial COM Input in QuickBASIC (45486)
The information in this article applies to:
- Microsoft QuickBASIC Compiler for the Apple Macintosh 1.0
- Microsoft BASIC Compiler
- Microsoft BASIC Interpreter for Apple Macintosh 2.0
- Microsoft BASIC Interpreter for Apple Macintosh 2.1
- Microsoft BASIC Interpreter for Apple Macintosh 3.0
This article was previously published under Q45486 SUMMARY
There are two RS-232 serial communications ports on each Apple
Macintosh system that are normally configured as one COM port and one
printer port.
Microsoft QuickBASIC Version 1.00 for the Apple Macintosh uses only
one port as the COM port and one as the printer port. Although these
two ports are physically and logically identical, QuickBASIC
recognizes only the first one as the COM port (telephone icon) and the
second as the printer port (printer icon).
You can use only the OPEN "COM1:baud,parity,data,stop" statement to
set the communications parameters (for input, output, and random
access) on the telephone icon port. On the printer port, marked with
the printer icon, QuickBASIC cannot change the baud rate, parity, data
bits, or stop bits. This limits input possibilities.
This information also applies to the Microsoft BASIC Compiler 1.00 for
the Macintosh and the Microsoft BASIC Interpreter Versions 2.00, 2.10,
and 3.00 for the Macintosh.
MORE INFORMATION
When the AppleTalk Network cable is connected to the printer port
(normal configuration), then the LLIST and LPRINT statements in
QuickBASIC send output to the COM port (to a directly connected Apple
ImageWriter printer only); and the "LPT1:" and "LPT1:PROMPT" device
names send output to the AppleTalk Network printer that is currently
selected in the Chooser (in the Apple menu).
| Modification Type: | Minor | Last Reviewed: | 8/16/2005 |
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| Keywords: | KB45486 |
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